You limited your search to:

 Decade: 1940-1949
 Serial/Series Title: NACA Technical Reports
 Collection: National Advisory Committee for Aeronautics Collection
Analysis of performance of jet engine from characteristics of components II : interaction of components as determined from engine operation

Analysis of performance of jet engine from characteristics of components II : interaction of components as determined from engine operation

Date: January 1, 1949
Creator: Goldstein, Arthur W; Alpert, Sumner; Beede, William & Kovach, Karl
Description: In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.
Contributing Partner: UNT Libraries Government Documents Department
An analytical method of estimating turbine performance

An analytical method of estimating turbine performance

Date: January 1, 1949
Creator: Kochendorfer, Fred D & Nettles, J Cary
Description: A method is developed by which the performance of a turbine over a range of operating conditions can be analytically estimated from the blade angles and flow areas. In order to use the method, certain coefficients that determine the weight flow and the friction losses must be approximated. The method is used to calculate the performance of the single-stage turbine of a commercial aircraft gas-turbine engine and the calculated performance is compared with the performance indicated by experimental data. For the turbine of the typical example, the assumed pressure losses and the tuning angles give a calculated performance that represents the trends of the experimental performance with reasonable accuracy. The exact agreement between analytical performance and experimental performance is contingent upon the proper selection of a blading-loss parameter.
Contributing Partner: UNT Libraries Government Documents Department
An apparatus for varying effective dihedral in flight with application to a study of tolerable dihedral on a conventional fighter airplane

An apparatus for varying effective dihedral in flight with application to a study of tolerable dihedral on a conventional fighter airplane

Date: January 1, 1949
Creator: Kauffman, William M; Liddell, Charles J , Jr; Smith, Allan & Van Dyke, Rudolph D , Jr
Description: An apparatus for varying effective dihedral in flight by means of servo actuation of the ailerons in response to sideslip angle is described. The results of brief flight tests of the apparatus on a conventional fighter airplane are presented and discussed. The apparatus is shown to have satisfactory simulated a wide range of effective dihedral under static and dynamic conditions. The effects of a small amount of servo lag are shown to be measurable when the apparatus is simulating small negative values of dihedral. However, these effects were not considered by the pilots to give the airplane an artificial feel. The results of an investigation employing the apparatus to determine the tolerable (safe for normal fighter operation) range of effective dihedral on the test airplane are presented.
Contributing Partner: UNT Libraries Government Documents Department
Application of Theodorsen's theory to propeller design

Application of Theodorsen's theory to propeller design

Date: January 1, 1949
Creator: Crigler, John L
Description: A theoretical analysis is presented for obtaining, by use of Theodorsen's propeller theory, the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. The efficiencies realized by designing for the optimum load distribution are given in graphs, and the optimum efficiency for any design condition may be read directly from the graph without any laborious calculations. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers.
Contributing Partner: UNT Libraries Government Documents Department
Appreciation and Prediction of Flying Qualities

Appreciation and Prediction of Flying Qualities

Date: January 1, 1949
Creator: Phillips, William H
Description: The material given in this report summarizes some of the results of recent research that will aid the designers of an airplane in selecting or modifying a configuration to provide satisfactory stability and control characteristics. The requirements of the NACA for satisfactory flying qualities, which specify the important stability and control characteristics of an airplane from the pilot's standpoint, are used as the main topics of the report. A discussion is given of the reasons for the requirements, of the factors involved in obtaining satisfactory flying qualities, and of the methods used in predicting the stability and control characteristics of an airplane. The material is based on lecture notes for a training course for research workers engaged in airplane stability and control investigations.
Contributing Partner: UNT Libraries Government Documents Department
Characteristics of low-aspect-ratio wings at supercritical Mach numbers

Characteristics of low-aspect-ratio wings at supercritical Mach numbers

Date: January 1, 1949
Creator: Stack, John & Lindsey, W F
Description: The separation of the flow over wings precipitated by the compression shock that forms as speeds are increased into the supercritical Mach number range has imposed serious difficulties in the improvement of aircraft performance. Three difficulties rise principally as a consequence of the rapid drag rise and the loss of lift that causes serious stability changes when the wing shock-stalls. Favorable relieving effects due to the three-dimensional flow around the tips were obtained and these effects were of such magnitude that it is indicated that low-aspect-ratio wings offer a possible solution of the problems encountered.
Contributing Partner: UNT Libraries Government Documents Department
Constant-pressure combustion charts including effects of diluent addition

Constant-pressure combustion charts including effects of diluent addition

Date: January 1, 1949
Creator: Turner, L Richard & Bogart, Donald
Description: Charts are presented for the calculation of (a) the final temperatures and the temperature changes involved in constant-pressure combustion processes of air and in products of combustion of air and hydrocarbon fuels, and (b) the quantity of hydrocarbon fuels required in order to attain a specified combustion temperature when water, alcohol, water-alcohol mixtures, liquid ammonia, liquid carbon dioxide, liquid nitrogen, liquid oxygen, or their mixtures are added to air as diluents or refrigerants. The ideal combustion process and combustion with incomplete heat release from the primary fuel and from combustible diluents are considered. The effect of preheating the mixture of air and diluents and the effect of an initial water-vapor content in the combustion air on the required fuel quantity are also included. The charts are applicable only to processes in which the final mixture is leaner than stoichiometric and at temperatures where dissociation is unimportant. A chart is also included to permit the calculation of the stoichiometric ratio of hydrocarbon fuel to air with diluent addition. The use of the charts is illustrated by numerical examples.
Contributing Partner: UNT Libraries Government Documents Department
Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement

Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement

Date: January 1, 1949
Creator: Lundin, Bruce T; Povolny, John H & Chelko, Louis J
Description: Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.
Contributing Partner: UNT Libraries Government Documents Department
Design and performance of family of diffusing scrolls with mixed-flow impeller and vaneless diffuser

Design and performance of family of diffusing scrolls with mixed-flow impeller and vaneless diffuser

Date: January 1, 1949
Creator: Brown, W Byron & Bradshaw, Guy R
Description: A family of diffusing scrolls was designed for use with a mixed-flow impeller and a small-diameter vaneless diffuser. The design theory, intended to maintain a uniform pressure around the scroll inlet, permits determination of the position of scroll cross sections of preassigned area by considering the radial variation in fluid density and the effects of friction along the scroll. Inasmuch as the design method leaves the cross-sectional shape undetermined, the effect of certain variations in scroll shape was investigated by studying scrolls having angles of divergence (of the scroll walls downstream of the entrance section) of 24 degrees, 40 degrees, and 80 degrees. A second 80 degree scroll was of asymmetrical construction and a third was plaster-cast instead of sand-cast. Each scroll was tested as a compressor component at actual impeller tip speeds of 700 to 1300 feet per second from full throttle to surge.
Contributing Partner: UNT Libraries Government Documents Department
The design of low-turbulence wind tunnels

The design of low-turbulence wind tunnels

Date: January 1, 1949
Creator: Dryden, Hugh L & Abbott, Ira H
Description: Within the past 10 years there have been placed in operation in the United States four low-turbulence wind tunnels of moderate cross-sectional area and speed, one at the National Bureau of Standards, two at the NACA Langley Laboratory, and one at the NACA Ames Laboratory. This paper reviews briefly the state of knowledge and those features which make possible the attainment of low turbulence in wind tunnels. Specific applications to two wind tunnels are described.
Contributing Partner: UNT Libraries Government Documents Department
FIRST PREV 1 2 3 4 5 NEXT LAST